#Snowpack/#Drought news: The latest briefing is hot off the presses from the Western Water Assessment

Water Year 2018 precipitation as a percent of normal through February 7, 2018.

Click here to read the current briefing (scroll down):

The latest monthly briefing was posted today on the Intermountain West Climate Dashboard. The highlights, also provided below, cover current snowpack and drought conditions, seasonal runoff forecasts, January precipitation and temperature, and ENSO conditions and outlooks.

  • After another month of sub-par precipitation and unusually warm temperatures, moderate to severe drought conditions have settled in across nearly all of Utah and most of Colorado. At this stage of the season, the near-record-low snowpack in many basins makes very low spring-summer runoff a likely outcome, while recovery to near-average conditions is extremely unlikely.
  • The snowpack in all Utah basins except for the Bear River and the northern Uintas, and in all Colorado basins south of I-70, is at near-record low conditions, with 30-55% of normal SWE. The Yampa-White appears better off at 75% of normal SWE, but this is still an unusually low value for that basin. The Colorado River headwaters, South Platte, and North Platte are closer to normal levels. Wyoming’s snowpack remains in good shape overall, with above-normal SWE in the northwest basins grading to somewhat below-normal SWE in the southern basins.
  • The seasonal runoff forecasts issued for February 1 by NRCS and NOAA show an increasing number of points in Utah and Colorado with less than 50% of average runoff expected, especially in the southern halves of the two states. Only a few forecast points in Utah, and about a third of those in Colorado, are expected to have more than 70% of average runoff. Forecasted runoff for Wyoming is generally above average or near average.
  • Weak to moderate La Niña conditions are continuing, with a transition back to ENSO-neutral conditions likely by late spring. Historically, weak to moderate La Niña events carry increased odds for below-normal March-May precipitation for Utah and Colorado, which is reflected in the CPC seasonal outlook for that period.
  • January brought overall below-normal precipitation and very warm conditions for Colorado and Utah, and near-average precipitation and warm conditions for Wyoming. The November-January period was the warmest on record for both Colorado and Utah (since 1895). This record warmth is reflected in the short- to mid-term EDDI maps, which show unusually high evaporative demand since November.
  • Since early January, drought conditions have worsened in northern and central Utah, and in southern and northwestern Colorado, while easing in northeastern Colorado. As of February 6, 94% of Utah is in D1 or D2, and the remainder in D0; in Colorado, 72% is in D1 or D2, and 27% in D0; and in Wyoming, only 5% is in D1, and 24% in D0. This drought footprint (D1 or worse) is the largest since early September 2013 in Colorado, and since April 2015 in Utah.
  • US Drought Monitor February 6, 2018.

    Leave a Reply